ball.push(new Ball(1,100,100,50));
setInterval(function () {
    if(bTop){
        ball[0].moveUp();
    }
    if(bBottom){
        ball[0].moveDown();
    }
    if(bLeft){
        ball[0].moveLeft();
    }
    if(bRight){
        ball[0].moveRight()
    }
    context.clearRect(0,0,gameWidth,gameHeight);
    ball[0].draw();
},10);
